1. Field of the Invention
The present invention concerns a sizer for stuffing flowable materials such as sausage into a flexible casing. More particularly, the invention concerns a horn assembly having inner and outer concentric tubes presenting an evacuation chamber therebetween connected to a vacuum source. The tubes are shiftable relative to one another between an open position in which the chamber communicates with the interior of the inner tube through an open space adjacent the discharge ends of the tubes for evacuating air from material within the inner tube, and a closed position in which the open space is sealed to prevent communication between the chamber and the inner tube interior thereby preventing entry of material into the chamber.
2. Description of the Prior Art
When stuffing flowable materials such as sausage and hamburger into a casing, residual air pockets can result in voids in the finished product and holes in the sliced product. Prior art devices and techniques attempt to keep the flowable materials under vacuum during processing and stuffing in order to remove excess air much as that shown in U.S. Pat. No. 5,035,671, the disclosure of which is hereby incorporated by reference. In so doing, however, the flowable material has a tendency to enter the vacuum passages which can plug the passages and create sanitation problems. Accordingly, the prior art points out the need for a sizer which removes air from the flowable product being stuffed without plugging vacuum lines and attendant sanitation problems